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Testes de corrida/caminhada de 6 e 9 minutos: validação e determinantes metabólicos em crianças e adolescentesLorenzi, Thiago Del Corona January 2006 (has links)
O entendimento da aptidão cardiorrespiratória em crianças e jovens é hoje uma estratégia fundamental de controle da saúde em geral. No entanto, avaliar a aptidão cardiorrespiratória, de forma direta, demanda um custo financeiro alto, pessoal especializado e um tempo excessivo. Nesta perspectiva, inúmeros estudos vêm propondo testes que avaliem, de forma indireta, a aptidão cardiorrespiratória de crianças e jovens. Assim, o objetivo geral do estudo foi compreender os testes de corrida/caminhada de 6 e de 9 minutos e as relações que estes estabelecem com o VO2máx, economia de movimento (EM) e limiar anaeróbio (LA). O estudo propõe uma abordagem de validação de técnica de medida. A amostra foi do tipo não aleatória por conveniência, de corte transversal. Foram avaliados 96 sujeitos, sendo 46 do sexo masculino e 50 do sexo feminino, na faixa etária de 10 a 14 anos de idade. O estágio maturacional foi determinado de acordo com a pilosidade púbica através de Tanner (1962). Os testes de corrida/caminha de 6 e de 9 minutos foram avaliados pela maior distância alcançada no tempo determinado de cada teste. Os componentes da aptidão cardiorrespiratória foram obtidos através de um teste em esteira de carga progressiva até a exaustão, acompanhado pelo ergoespirômetro MedGraphics Cardiorespiratory Diagnostic Systems, modelo MGC/CPX-D. O valor médio de VO2 registrado durante o 4° minuto, a uma velocidade constante, foi considerado o valor de EM. VO2máx que foi obtido pelo maior valor alcançado durante o teste. O limiar ventilatório (LV) foi entendido como o VO2 expresso pelo segundo ponto de inflexão na curva de ventilação e do custo ventilatório de CO2 de cada indivíduo. Para todas as análises estatísticas foi utilizado o programa estatístico SPSS for Windows 10.0. O nível de significância adotado foi de 5%. Os principais resultados apontam que os índices alcançados no teste de 9 minutos (r= 0,632) apresentam melhor relação com o VO2máx de simples razão (ml.kg-1.min-1 ou kg-1) do que os mesmos no teste de 6 minutos (r=0,393). No entanto, o valor de r aumenta para 0,704 e 0,728 nos testes de 6 e de 9 minutos, respectivamente, quando os relacionamos com o VO2máx em expoentes alométricos (kg-0,67). Quanto ao comportamento dessas variáveis durante a puberdade, notamos incremento nos dois testes aeróbios e no VO2máx quando expresso em kg-0,67. No VO2máx (kg-1), os valores médios durante a puberdade se mantiveram estáveis. Quanto às diferenças entre os sexos, percebemos que os valores obtidos pelos meninos superam os das meninas em todas as variáveis. No entanto, percebemos que as diferenças são potencializadas quando expressamos o VO2máx em escalas alométricas (kg-0,67). No âmbito dos componentes da aptidão cardiorrespiratória constatamos que o VO2máx (kg-0,67), aliado a EM (%VO2máx) foram as variáveis que apresentaram maior poder preditivo sobre os testes aeróbios de campo analisados neste estudo, representando geralmente mais de 60% da explicação desses. Já o LV não estabeleceu relações suficientemente capazes de ser apontado como variável preponderante no desempenho dos testes de corrida/caminhada de 6 e de 9 minutos. Dessa forma, podemos concluir que os dois testes analisados são válidos para a avaliação da aptidão cardiorrespiratória se assumirmos que o VO2máx é mais bem representado pelo expoente de massa corporal kg-0,67. Além disso, constatamos que a EM, aliado à capacidade aeróbia máxima é fundamental no desempenho de testes de características aeróbias. Sendo assim, podemos sugerir a utilização do teste de corrida de 6 minutos à professores de educação física como parâmetro da aptidão cardiorrespiratória de seus alunos, pois além de ser um teste simples, de fácil compreensão e que permite sua aplicação em diferentes estruturas físicas, apresentou uma alta relação com o consumo máximo de oxigênio (kg-0,67). / The knowledge about the cardiorespiratory fitness in children and adolescents is a basic strategy of control of the health, considering that low indices of this capacity in this period of age can point important associations with hypokinetic disease in the adult age. However, to evaluate the cardiorespiratory fitness by direct methods demand a high financial cost, specialized people and excessively time. In this perspective, innumerable studies has been considering tests that measure by indirect methods the cardiorespiratory fitness of children and adolescents. Thus, the general objective of this study was to understand the of Run/walk in 6 minutes and Run/walk in 9 minutes tests and the relations that these establish with the VO2max. Moreover, we tried to identify the variables capable to determine the performance of both tests in individuals in the period of infancy and adolescence. The study considers an approach of validation of measuring technique. The sample was a not random type for convenience, with transversal cut analysis. 96 subjects had been evaluated, being 46 masculine and 50 feminine, with ages between 10 and 14 years old. The maturational status was determined by pubic hair according to Tanner (1962). The tests of Run/walk in 6 minutes and Run/walk in 9 minutes had been understood by the biggest distance reached in the definitive time of each test. The components of the cardiorespiratory fitness were gotten through a gradual load test in treadmill until the exhaustion, measured through a gas meter model (MedGraphics Cardiorespiratory Diagnostic Systems – MGC/CPX-D). The average value of VO2 registered during the 4th minute, in a constant speed, was considered the value of movement economy (ME). The VO2max was gotten by the highest value reached during the test. The ventilatory threshold was understood as the VO2 expressed for the second point of inflection in the curve of ventilation and CO2 ventilatory cost for each individual. For all the statistical analyses the statistical program SPSS for Windows 10.0 was used. The level of significance adopted for all the analyses was of 5%. The main results point that the indices reached in the test of 9 minutes (r = 0,632) present better relationship with the VO2max of simple reason (ml.kg-1.min-1 or kg-1) than the same ones in the test of 6 minutes (r=0,393). However, the value of r increases for 0,704 and 0,728 in the tests of 6 and 9 minutes, respectively, when we relate them with the VO2max in allometric exponents (kg-0,67). About the behavior of these variables during the puberty, we notice an increment in the two aerobic tests and in the VO2max expressed in kg-0,67. In the VO2max (kg-1), the average values during the puberty remained steady. About the differences between sexes, we perceive that the values gotten for the boys surpass of the girls in all variables. However, we perceive that the differences are powered when we express the VO2max in allometric scales (kg-0,67). About the components of the cardiorespiratory fitness, we evidence that the VO2max (kg-0,67), ally to the ME (%VO2max) had been the variables that had presented greater predictive power on the field aerobic tests analyzed in this study, representing generally more than 60% of the explanation of these. However, the ventilatory threshold did not establish relationships capable enough to be pointed as the preponderant variable in the performance of Run/walk in 6 minutes and Run/walk in 9 minutes tests. This way, we can conclude that the two analyzed tests are valid for the evaluation of the cardiorespiratory fitness if we assume that the VO2max is better represented by the allometric scales. Moreover, we evidence that the movement economy, ally to the maximum aerobic capacity is basic in the performance of aerobic characteristics tests. Thus, we can suggest the use of the Run/walk in 6 minutes test to any physical education teacher as a parameter of the cardiorespiratory fitness of his students, therefore it is a simple test, of easy understanding, that allows its application in different physical structures and it shows excellent relationship with the maximum oxygen consumption (kg-0,67).
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Účinné průřezy srážek elektronů s atomy vodíku / Účinné průřezy srážek elektronů s atomy vodíkuBenda, Jakub January 2012 (has links)
Although the collisions of electrons and atomic hydrogen has been studied for several decades, there is still neither a complete database of scattering data, nor a universal method that would let generate such data. For astronomical and other purposes the cross sections of electron-hydrogen collisions are necessary, in a broad range of energies - from tenths of electronvolt to millions of electronvolts. In this work the author concentrates on several established approaches to electron-atom scattering and confronts results of his own implementations of these methods against the published data and results of freely available computer codes. A special attention is given to the overlaps of different methods, so that in the end a database with easy user interface can be offered for common practical usage of scattering data in applied fields.
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NONLINEAR SCALING IN SOCIAL PHYSICS / NONLINEAR SCALING IN SOCIAL PHYSICSHygor Piaget Monteiro Melo 26 August 2016 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / As aplicaÃÃes da mecÃnica estatÃstica no estudo do comportamento humano coletivo nÃo sÃo uma novidade. No entanto, nas Ãltimas dÃcadas vimos um aumento enorme do interesse no estudo da sociedade usando a fÃsica. Nesta tese, utilizando tÃcnicas da fÃsica, nÃs estudamos leis de escala nÃo-lineares em sistemas sociais. Na primeira parte da tese realizamos a anÃlise de dados e modelagem de eleiÃÃes pÃblicas. Mostramos que o nÃmero de votos de um candidato escala nÃo-linearmente com o dinheiro gasto na campanha. Para nossa surpresa, a correlaÃÃo revelou uma relaÃÃo de escala sublinear, o que significa que o "preÃo" mÃdio de um voto cresce à medida que o nÃmero de votos aumenta. Usando um modelo de campo mÃdio descobrimos que a nÃo-linearidade emerge da concorrÃncia e a distribuiÃÃo de votos à causalmente determinada pela distribuiÃÃo do dinheiro gasto na campanha. AlÃm disso, mostramos que o modelo à capaz de prever razoavelmente o nÃmero final de votos vÃlidos atravÃs de um argumento heurÃstico simples. Por fim, apresentamos o nosso trabalho sobre alometria de indicadores sociais. NÃs mostramos como homicÃdios, mortes em acidentes de carro e suicÃdios crescem com a populaÃÃo das cidades brasileiras. Diferentemente de homicÃdios
(superlinear) e eventos fatais em acidentes de carro (isomÃtrico), encontramos
um comportamento sublinear entre o nÃmero de suicÃdios e a populaÃÃo de cidades, o que revela uma possÃvel evidÃncia de influÃncia social na ocorrÃncia de suicÃdios. / The applications of statistical mechanics in the study of collective human behavior is not a novelty. However, in the past few decades we shaw a huge spike of interest on the study of society using physics. In this thesis we explore nonlinear scaling laws in social systems using physical techniques. First we perform data analysis and modeling applied to elections. We show that the number of votes
of a candidate scales nonlinear with the money spent at the campaign. To our surprise, the correlation revealed a sublinear scaling, which means that the average âpriceâ of one vote grows as you increase the number of votes.
Using a mean-field model we find that the sublinearity emerges from the competition and the distribution of votes is causally determined by the distribution of money campaign. Moreover, we show that the model is able to reasonably predict the final number of valid votes
through a simple heuristic argument. Lastly, we present our work on allometric scaling of social indicators. We show how homicides, deaths in car crashes, and suicides scales with the population of Brazilian cities. Differently
from homicides (superlinear) and fatal events in car crashes (isometric), we find sublinear scaling behavior between the number of suicides and city population, which reveal a possible evidence for social influence on suicides occurrences.
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A teia Browniana radial / The Radial Brownian WebLeón Alexander Valencia Henao 29 February 2012 (has links)
Introduzimos uma familia de trajetorias aleatorias coalescentes com certo tipo de comportamento radial a qual chamaremos de Teia Poissoniana radial discreta. Mostramos que o limite fraco na escala difusiva desta familia e uma familia de trajetorias aleatorias coalescentes que chamaremos de Teia Browniana radial. Por m, caraterizamos o objeto limite como um mapeamento continuo da Teia Browniana restrita num subconjunto de R2. / We introduce a family of coalescing random paths with certain kind of radial behavior. We call them the discrete radial Poisson Web. We show that under diusive scaling this family converges in distribution to a family of coalescing random paths which we call radial Brownian Web. Finally, we characterize the limiting object as a continuous mapping of the Brownian Web restricted to a subset of R2.
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Limite de escala do modelo de armadilhas numa árvore / Scaling limit of the trap model on a treeRenato Jacob Gava 21 October 2011 (has links)
Nós apresentamos o processo K numa árvore, que é um processo de Markov com estados instantâneos e generaliza o processo K no grafo completo, como o limite do modelo de armadilha numa árvore, e aplicamos esse resultado para derivar um limite de escala para o modelo de armadilha do GREM. / We present the K process on a tree, which is a Markov process with instantaneous states and generalises the K process on the complete graph, as a limit of the trap model on a tree, and apply this result to derive a scaling limit to the GREM-like trap model.
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Homem e obesidade - excesso e faltas: corpos que contam histórias / Man and obesity excess and paucity: (the) bodies that tell stories.Simone Peixoto Conejo 29 April 2009 (has links)
Este estudo buscou compreender a associação entre obesidade e variantes da eficácia da adaptação em homens adultos entre 30 e 50 anos. Utilizou como instrumentos a Escala Diagnóstica Adaptativa Operacionalizada Revisada (EDAO-R), a Entrevista Preventiva, a Escala de Avaliação Global do Funcionamento (AGF) e a Escala Toronto de Alexitimia (ETA-20). Contou com a colaboração de quatro sujeitos do sexo masculino, com idades entre 30 e 42 anos. Três sujeitos participaram desse estudo por meio da empresa em que trabalham e um foi contatado por intermédio de um profissional de saúde. Os resultados obtidos mostram que a obesidade está associada, predominantemente, a aspectos afetivos. Entre os setores adaptativos prepondera, então, como o mais importante, o setor Afetivo-Relacional. Todos apresentaram esse setor como pouquíssimo adequado. A pouquíssima adequação encontrada nesse setor repercute, nesses sujeitos, no setor Orgânico. O setor Produtivo também recebe interferências e apresenta prejuízos em dois dos participantes do estudo. Deste modo, concluímos que os fatores emocionais corroboram com a instalação e manutenção da obesidade. / This study aimed to understand the association between obesity and effectiveness variants of adaptation in male adults between 30 and 50 years old. It used as instruments the Operational Adaptive Diagnostic Scale Revised (OADS-R), the Preventive Interview, the Global Assessment Scale of Functioning (GAF), and the Toronto Scale of Alexithymia (TSA-20). It had the cooperation of four male subjects, aged between 30 and 42. Three subjects took part in this study through the company where they worked, and one was contacted by a health professional. The results show that obesity is mainly associated with affective aspects. Among adaptive sectors, therefore, the Affective-Relational sector preponderates as the most important one. They all presented this sector as considerably inappropriate. This very little appropriation reverberates, in these subjects, in the Organic sector. The Productive sector also receives interferences and presents damages in two participants of the study. Consequently, we came to the conclusion that emotional factors corroborate with obesity presentation and maintenance.
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Energy and speed exploration in digital CMOS circuits in the near-threshold regime for very-wide voltage-frequency scalingStangherlin, Kleber Hugo January 2013 (has links)
Esta tese avalia os benefícios e desafios associados com a operação em uma ampla faixa de frequências e tensões próximas ao limiar do transistor. A diminuição da tensão de alimentação em circuitos digitais CMOS apresenta grandes vantagens em termos de potência consumida pelo circuito. Esta diminuição da potência é acompanhada por uma redução da performance, reflexo da diminuição na tensão de alimentação. A operação de circuitos digitais no ponto de energia mínima é comumente associada ao regime de operação abaixo do limiar do transistor, trazendo enormes penalidades em performance e variabilidade. Esta dissertação mostra que é possível obter 8X mais eficiência energética com uma ampla faixa dinâmica de tensão e frequência, da tensão nominal até o limite inferior da operação próximo ao limiar do transistor. Como parte deste estudo, uma biblioteca de células digitais CMOS para esta ampla faixa de frequências foi desenvolvida. A biblioteca de células lógicas foi exercitada em um PDK comercial de 65nm para operação próximo ao limiar do transistor, reduzindo os efeitos da variabilidade sem comprometer o projeto em termos de área e energia quando operando em inversão forte. Para operar próximo e abaixo do limiar do transistor as células devem ser desenvolvidas com um número limitado de transistores em série. Nosso estudo mostra que uma performance aceitável em termos de margens de ruído estático é obtida para um conjunto restrito de células, onde são empregados no máximo dois transistores em série. Reportamos resultados para projetos de média complexidade que incluem um filtro notch de 25kgates, um microcontrolador 8051 de 20kgates, e 4 circuitos combinacionais/ sequenciais do conjunto de avaliação ISCAS. Neste trabalho, é estudada a máxima frequência atingida em cada tensão de alimentação, desde 0.15V até 1.2V. O ponto de mínima energia é demonstrado em operação abaixo do limiar do transistor, aproximadamente 0.29V, oque representa um ganho de 2X em eficiência energética comparado ao regime de operação próximo ao limiar do transistor. Embora o pico de eficiência energética ocorra abaixo do limiar do transistor para os circuitos estudados, nós também demonstramos que nesta tensão de alimentação ultra-baixa o atraso e a potência sofrem um impacto substancial devido ao aumento na variabilidade, atigindo uma degradação em performance de 30X, com respeito à operação próxima ao limiar do transistor. / This thesis assesses the benefits and drawbacks associated with a very wide range of frequency when operation at near-threshold is considered. Scaling down the supply voltage in digital CMOS circuits presents great benefits in terms of power reduction. Such scaling comes with a performance penalty, hence in digital synchronous circuits the reduction in frequency of operation follows, for a given circuit layout, the VDD reduction. Minimum-energy operation of digital CMOS circuits is commonly associated to the sub-VT regime, carrying huge performance and variability penalties. This thesis shows that it is possible to achieve 8X higher energy-efficiency with a very-wide range of dynamic voltage-frequency scaling, from nominal voltages down to the lower boundary of near-VT operation. As part of this study, a CMOS digital cell-library for such wide range of frequencies was developed. The cell-library is exercised in a 65nm commercial PDK and targets near-VT operation, mitigating the variability effects without compromising the design in terms of area and energy at strong inversion. For near-VT or sub-VT operation the cells have to be designed with few stacked transistors. Our study shows that acceptable performance in terms of static-noise margins is obtained for a constrained set of cells, for which a maximum of 2-stacked transistors are allowed. In this set we include master-slave registers. We report results for medium complexity designs which include a 25kgates notch filter, a 20kgates 8051 compatible core, and 4-combinational/4-sequential ISCAS benchmark circuits. In this work the maximum frequency attainable at each supply for a wide variation of voltage is studied from 150mV up to nominal voltage (1.2V). The sub-VT operation is shown to hold the minimum energy-point at roughly 0.29V, which represents a 2X energy-saving compared to the near-VT regime. Although energy-efficiency peaks in sub-VT for the circuits studied, we also show that in this ultra-low VDD the circuit timing and power suffer from substantially increased variability impact and a 30X performance drawback, with respect to near-VT.
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Scaling the pitch for junior cricketersHarwood, Michael J. January 2018 (has links)
Although cricket is played around the world by all ages, very little attention has been focused on junior cricket. The research presented here evaluated the effects on junior cricket of reducing the pitch length, developed a method for scaling the pitch to suit the players and applied this method to the under-11 age group. In the first of four studies it was established that shortening the cricket pitch had positive effects for bowlers, batters and fielders at both club and county standards, consequently resulting in matches that were more engaging. The second study found that top under-10 and under-11 seam bowlers released the ball on average 3.4° further below horizontal on a 16 yard pitch compared with a 19 yard pitch. This was closer to elite adult pace bowlers release angles and should enable junior players to achieve greater success and develop more variety in their bowling. The third study calculated where a good length delivery should be pitched to under-10 and under-11 batters in order to provoke uncertainty, and also examined the influence of pitch length on batters decisions to play front or back foot shots according to the length of the delivery. A shorter pitch should strengthen the coupling between the perception of delivery length and appropriate shot selection, and the increased task demand should lead to improved anticipation; both are key features of skilled batting. In the final study a method of calculating the optimal pitch length for an age group was developed which used age-specific bowling and batting inputs. This was applied to scale the pitch for under-11s giving a pitch length of 16.22 yards (14.83 m), 19% shorter than previously recommended for the age group by the England and Wales Cricket Board. Scaled in this way across the junior age groups, pitch lengths would fit the players better as they develop, enabling more consistent ball release by bowlers and temporal demands for batters, as well as greater involvement for fielders.
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Effect of Violating Unidimensional Item Response Theory Vertical Scaling Assumptions on Developmental Score ScalesTopczewski, Anna Marie 01 July 2013 (has links)
Developmental score scales represent the performance of students along a continuum, where as students learn more they move higher along that continuum. Unidimensional item response theory (UIRT) vertical scaling has become a commonly used method to create developmental score scales. Research has shown that UIRT vertical scaling methods can be inconsistent in estimating grade-to-grade growth, within-grade variability, and separation of grade distributions (effect size) of developmental score scale. In particular the finding of scale shrinkage (decreasing within-grade score variability as grade-level increases) has led to concerns about and criticism of IRT vertical scales. The causes of scale shrinkage have yet to be fully understood. Real test data and simulation studies have been unable to provide complete answers as to why IRT vertical scaling inconsistencies occur. Violations of assumptions have been a commonly cited potential cause for the inconsistent results. For this reason, this dissertation is an extensive investigation into how violations of the three assumptions of UIRT vertical scaling - local item dependence, unidimensionality, and similar reliability of grade level tests - affect estimated developmental score scales.
Simulated tests were developed that purposefully violated a UIRT vertical scaling assumption. Three sets of simulated tests were created to test the effect of violating a single assumption. First, simulated tests were created with increasing, decreasing, low, medium, and high local item dependence. Second, multidimensional simulated tests were created by varying the correlation between dimensions. Third, simulated tests with dissimilar reliability were created by varying item parameters characteristics of the grade level tests. Multiple versions of twelve simulated tests were used to investigate UIRT vertical scaling assumption violations. The simulated tests were calibrated under the UIRT model to purposefully violate an assumption of UIRT vertical scaling. Each simulated test version was replicated for 1000 random examinee samples to assess the bias and standard error of estimated grade-to-grade-growth, within-grade-variability, and separation-of-grade-distributions (effect size) of the estimated developmental score scales.
The results suggest that when UIRT vertical scaling assumptions are violated the resulting estimated developmental score scales contain standard error and bias. For this study, the magnitude of standard error was similar across all simulated tests regardless of the assumption violation. However, bias fluctuated as a result of different types and magnitudes of UIRT vertical scaling assumption violations. More local item dependence resulted in more grade-to-grade-growth and separation-of-grade-distributions bias. And local item dependence resulted in developmental score scales that displayed scale expansion. Multidimensionality resulted in more grade-to-grade-growth and separation-of-grade-distributions bias when the correlation between dimensions was smaller. Multidimensionality resulted in developmental score scales that displayed scale expansion. Dissimilar reliability of grade level tests resulted in more grade-to-grade-growth bias and minimal separation-of-grade-distributions bias. Dissimilar reliability of grade level tests resulted in scale expansion or scale shrinkage depending on the item characteristics of the test. Limitations of this study and future research are discussed.
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Development of the Multicultural Gender Role Scale for Asian American Women (MGRS-AAW)Rooney, Joanna Catherine Min Jee January 2019 (has links)
In an attempt to address the dearth of research examining the development and effects of intersectional, multiple marginalized identities, the scale developed in this study quantified the cultural variation in gender role expression of Asian American women. The following describes the development of the Multicultural Gender Role Scale for Asian American women (MGRS-AAW). The scale was conceptualized and largely constructed based on existing research: with specific attention regarding the qualitative themes and findings of Corpus and Miville (2013). A total of 71 items were administered to a sample of 327 participants who identified as Asian/Asian American women. Results were subjected to an Exploratory Factor Analysis and a total of 26 items were retained. Four independent constructs emerged, which closely mirrored and delineated the findings of the qualitative study: 1) Bicultural conflict, 2) Passivity, 3) Asian Values, and 4) Awareness. Further psychometric evaluation of the scale resulted in convergent validity of the subscales with other measures, such as the Attitudes Toward Women Scale (AWS) and the Asian American Racism Related Inventory (AARRSI), and discriminant validity was proven in regard to the lack of correlation among subscales with collected Grade Point Average. Findings were discussed in relation to strengths and weaknesses of the study, implications for the field, and future areas of studies.
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